Adjustable clamps



Jan. 24, 1956 G. J. SUTTON ADJUSTABLE CLAMPS Filed June 2, 1952 INVEN TOR United States Patent() ADJUSTABLE CLAMPS Gerald John Sutton, London, England, assignor to Grifin & George Limited, London, England, a British company Application June 2, 1952, Serial No. 291,208

Claims priority, application Great Britain .lune 7, 1951 4 claims. (ci. z4z47) This invention relates to adjustable clamps particularly for use in laboratories and of the kind comprising a jaw fixed to a rod which may be secured to a stand, another jaw pivoted to the first said jaw or to said rod so that the jaws may be brought together or separated, and a screw jack between the paws to effect said movement. An object of the invention is to provide a construction of a clamp which is simple and cheap to manufacture.

According to this invention, an adjustable clamp of the kind referred to is characterised in that part of each jaw comprises two plates spaced apart, the extremities of the spaced plates on one jaw being arranged to straddle a lug extending laterally of said rod to which lug they are pivoted, trunnions rotatably mounted between each pair of plates and a screw jack associated with the two trunnions.

Preferably, the aforesaid lug is formed integrally with one of the jaws. The aforesaid screw jack may comprise a spindle formed with oppositely threaded portions along the length thereof, which threaded portions engage oppositely threaded bores in said trunnions.

In a preferred form of construction, each said jaw is formed from two plates stamped from sheet metal, which plates are spaced apart at required locations by suitable spacing elements and are held together by securing means. The means for securing the two plates together may comprise rivets extending through holes in said plates.

The extremities of one pair may lie fiat against one another so that they may pass between the extremities of the pair of other plates which are spaced apart. The other ends of one pair of plates may be so shaped as to provide a socket for the aforesaid rod and a securing rivet may extend through said rod and through the walls of the socket.

The socket portion of the two plates may be provided with laterally extending ears which abut one another and form the aforsaid lug. The spaced portions of each pair of plates may be bridged at the base of the jaws so as to provide gripping by platforms which are preferably roughened and which lie flat against one another at the inner limit of movement of the jaws.

Niches may be formed in the adjacent edges of the two pairs of plates so as to grip small rods or tubes when the jaws approach one another.

The extremities of the jaws may be covered by rubber tubing in known manner.

In the case where the screw jacks are provided with quick pitch thread and are thus required to be of ap= preciable diameter, the aforesaid plates as they extend away from the socket portion in the one case and from the lug in the other case are provided with outward inflexions so that they are spaced apart suiciently to accommodate the screw jack and the trunnions with which they engage.

The following is a description of two alternative forms of clamp according to the invention reference being made to the accompanying drawing in which-` Figure l is a perspective view on one form of clamp, and

Figure 2 is a perspective view of another form of clamp.

Referring to the arrangement shown in Figure 1, the clamp comprises four main integers, two jaws 10 and 11, a supporting rod 12 attached to one jaw and a screw jack 13.

Each of the jaws is formed from two mild steel plates which are stamped and pressed into the required shape. The outer gripping sections 14 of the plates forming the jaw 10 are arranged to abut one another, while the` inner extremities 15 are splayed apart and straddle two. lug portions 16 formed at the inner extremity of the other jaw 11 to which they are secured by a fulcrum. pin 17. Each of the plates forming the jaw 10 are provided with a hole for receiving a trunnion member 18 which is inserted before the two plates are secured to thelug portions 16. The two plates are further held together by a rivet 19 and are spaced the required distance apart by inwardly bent lugs 20 formed on the two plates. The two plates are shaped to provide two gripping faces 21, 22 at an angle to one another and capable of gripping a comparatively large object. The faces are so disposed that a line passing normal to the axis of rotation through the points of contact of the faces with any sized article passes through the axis of the pivot pin 17 one such line being indicated at 23.

As indicated above, the other jaw member 11 is also formed from two plates, which are so shaped that the outer extremities 24 are spaced apart, so as to enable the outer extremity of the other jaw part 10 to pass between them. Each of the plates may be provided with V-shaped gripping faces 21 and 22 as described with reference to jaw 10. Each of the plates at its inner extremity is provided with the aforesaid lug 16, and with another lug 25 which is shaped to form a socket portion for the rod 12. A rivet 26 is arranged to pass through the lugs and through a hole in the rod. Another trunnion member 27 is rotably mounted in holes formed in the two plates. The two plates are additional secured together by a further rivet 28. The two plates are provided with inwardly bent ears 29 and 30 on opposite sides thereof adjacent the rivet 28, and further ears 31 are provided adjacent the socket part 25 so as to space the plates at a required distance apart. The fulcrum members 18 and 27 are provided with cross bores which are internally threaded with opposite handed threads. The aforesaid screw jack comprises a spindle which has oppositely handed threads 0n either side of a centre portion 32. One extremity of this threaded rod engages a socket on a manipulating piece 33 and is held in position by a pin 34.

Each of the plates of the two jaws 10 and 11 are provided with niches 35 for gripping small diameter rods or tubes when the jaws are brought together. The gripping extremities of both jaws may be covered with rubber tubing.

With the above arrangement, when the jaws are clamped upon a cylindrical article a six point engagement results, four points on the jaw 11 and two points on the jaw 10.

The arrangement shown in Figure 2 is very similar to that described above with the exception that each jaw part 10 and 11 is formed from a die casting avoiding the necessity of rivet for holding the two plates together, since the spacing members 36 are cast integrally with the plates, as is also the socket portion 37 and lug 16 on the jaw part 11. The inner faces of the spacing members 36 are serrated as indicated at 41 in order to provide a vise in addition to the niches 35. As in the previous construction the screw jack 13 is provided with two oppositely threaded portions 38 and 39 which in this instance are of different diameters. In place of the flat manipulating piece of the previous construction, the screw jack is provided with a cross bar 40. The arrangement and disposition of the flat gripping faces 21 and 22 are similar to the previous construction. l

, Iclaim:

1. An adjustable clamp comprising a rod, two jaws, each of which jaws is formed.so1e1yfrom two separate sheet metal plates, spacing means between each pair of plates, securing means holding the two plates together, one pair of which plates is formed both with a socket which grips the end of the rod, and a lug projecting from the socket, a pivotal connection between said lng and one end of the other jaw, a trunnion pivotally mounted between each pair of plates and disposed away from said pivotal connection, which trunnions are provided with opposite threaded bores and a'screw jack engaging said threaded bores.

2. An adjustable clamp according to claim 1 wherein said spacing means comprise lugs formed integrally with the plates and wherein said projection on said socket is formed by two ears extending respectively from the two plates and abutting one another.

3. An adjustable clamp according to claim 1 wherein the outer extremity of each jaw is provided with two gripping faces arranged at an angle toone another, and so disposed in relation to the pivotal connection, that a line passing normal to the axis of rotation through the two areas of contact between any circular article gripped by said two gripping faces intersects the axis of said pivotal connection.

4. An adjustable clamp according to claim 1 wherein the outer extremities of one pair of plates in one jaw lie at against one another, whereas the outer extremities of the other pair of plates of the other jaw are spaced apart and are adapted to permit the extremity of the other jaw to pass between them.

References Cited inthe file of this patent UNITED STATES PATENTS 705,932 Kennedy -July 29, 1902 722,349 Young Mar. 11, 1903 795,782 Porter July 25, 1905 868,945 Sewall Oct. 22, 1907 887,103 Lane May 12, 1908 1,162,059 Herseyr Nov. 30, 1915 1,246,325 Rohmer Nov. 13, 1917 1,386,084 Adamson Aug. 2, 1921 1,409,233 Pataky Mar. 14, 1922 1,895,156 Fisher Ian. 24, 1933 FOREIGN PATENTS 219,939 Germany Mar. 1l, 1910 

